New sedimentary rock made from slag is a carbon-trapping champ Premium
The Hindu
Scientists study how industrial waste like slag hardens into sedimentary rocks, adversely affecting the environment but also trapping carbon.
Human activity has significantly altered the earth’s landscape — so much so that many scientists have said the planet began a new geological chapter called the Anthropocene era.
Many of these changes have been wrought by deposits of materials like industrial waste and construction debris. These materials weather over time and mix with natural sediment, and affect the environment by changing the acidity of soil and water, the composition of soil, and the distribution of minerals.
In 2015, artificial ground contributed more than 316 million tonnes of sedimentary material to the oceans, far exceeding the natural supply.
But going beyond simply being abundant in the natural environment, scientists have been documenting some unusual formations that wouldn’t have taken shape if not for the trash humans are throwing out. In a recent study in the journal Sedimentologika, for example, researchers documented a new kind of sedimentary rock made from coastal slag deposits in the U.K.
This rock follows other formations like molten glass and steel in the refuse of nuclear weapon tests and pieces of plastic pieces floating in oceans that disease-causing bacteria have grabbed hold of.
Slag is a major component of artificial ground. It is a composite material containing metal oxides and silicon dioxide, and is a by-product of the steelmaking process in the iron and steel industries.
At Warton, England, old industrial waste sites are the focus of a unique study examining slag hardening, or lithification.